PSA velocity found poor predictor of prostate cancer

PSA velocity is a poor predictor of prostate cancer and may lead to many unnecessary biopsies, according to a recent study.

"We have found no evidence to support the recommendation that men with a high PSA velocity should be biopsied in the absence of other indications," said lead author Andrew Vickers, PhD, of Memorial Sloan-Kettering Cancer Center, New York. "In other words, if a man’s PSA has risen rapidly in recent years, there is no cause for concern if his total PSA level is still low and his clinical exam is normal."

The study included 5,519 men from the Prostate Cancer Prevention Trial who were 55 years of age and older. All of the men had no previous prostate cancer diagnosis, a normal digital rectal exam, and a baseline PSA of 3.0 ng/mL or less. They were randomly assigned to finasteride (Proscar) or placebo for 7 years. The men were followed with yearly PSA tests, with biopsy recommended for men with a PSA higher than 4.0 ng/mL. After 7 years, all men who were not diagnosed with prostate cancer were asked to consent to an end-of-study biopsy.

Dr. Vickers and colleagues found no important association between PSA velocity and biopsy outcome after adjusting for risk factors such as age, race, and PSA levels. PSA alone was a much better predictor of biopsy outcome than PSA velocity.

"This study should change practice," said Peter T. Scardino, MD, also of Memorial Sloan-Kettering, whose National Cancer Institute grant helped fund the study. "We have previously published papers determining that PSA naturally varies from month to month and have urged men whose PSA suddenly rises to wait 6 weeks and repeat the test before agreeing to a needle biopsy. This new study in a large population of men provides even stronger evidence that using changes in PSA as a basis for recommendation for biopsy leads to many more unnecessary biopsies and does not help to find the more aggressive cancers that we want to find and treat."

Results from the study were published online in the Journal of the National Cancer Institute (Feb. 24, 2011).